Thread anvil



Nov. 14, 1950 c. RUSSELL ET AL 2,530,267

THREAD ANVIL Filed March 21, 1946 lmlmlmh INVENTORS Cfi/fL RUSSELL a fl/M/S A. AIEL ATTD RN EYS Patented Nov. 14, 1950 UNITED- STATES PATENT GFF'ICE I m 2,530,207 v 4 1 TH 7 Carl Russell and Hans R. Kiel, Downev,-Calif. Application March 21, 1946, Se'rial No. 656,083

This invention relates to a screw thread anvil or gauge which is adapted to be used in measuring the pitch line of various threads.

An object of the invention is to provide a device which when used in conjunction with a micrometer caliper will determine the exact pitch of the thread being measured.

Another object of the invention is to provide a device that is simple in construction, efficient in operation, reliable in use and economical to manufacture.

With the above and other objects and advantages in view the invention consists of the novel details of construction, arrangement and combination of parts more fully hereinafter described, claimed and illustrated in the accompanying drawing in which:

Figure l is a side view of an embodiment of the invention;

Figure 2 is a plan view thereof;

Figure 3 shows the device in use with a tap to be gauged and a micrometer caliper and Figure 4 is a sectional view on the line 44 of Figure 3;

Referring more in detail to the drawing the reference numeral indicates the thread engaging anvil which is triangular in shape having the nearly sharp or slightly blunt edge l2, the edge It increasing in width over the edge l2, and the edge [6 increasing in width over the edge I4. The anvil It! being of triangular shape comprises three faces. Face l5 extending from edge I 6 to edge 14, face I! extending from edge 14 to edge I2 and face l9 extending from edge [2 to edge H5.

The anvil II] is provided with a bushing I! shown in dotted lines in Figure 2 which is rotatably mounted on a shaft l8 which is fixed in the forked ends 29 of the handle 22. The bushing I! is so mounted on the shaft that the anvil is free to rotate as desired.

When the anvil is to be used it is positioned as shown in Figure 3 with the anvil positioned between micrometer screw 24 and the tap 26, which is adapted to rest on the lower tip 28 of the micrometer 30.

The anvil is made of hardened metal and is ground to a perfect angle of 60 and the three edges previously mentioned are ground to prevent them from touching the root of the thread of the tap to be measured.

To use the anvil it is placed in the thread on top of the tap to be measured and the edge is used which does not touch the bottom of the thread. The spindle of the micrometer is placed 1 Claim. (01. 33-107) on-th "501011 and the pin of the micrometer on the bottom of the tap the micrometer and anvil is rolled to get the exact center and the micrometer reading is taken.

In using the anvil, the followin formula is used:

Constant .10825 Pitch or T T ggg .10825 Plus Single T Depth A or face 15:1" B or face 16=AX.866

Formula:

B-' +sing1e depth=C C+major diameter=micrometer size.

EwampZe.-Find mike size for 1%" dia., 7 threads per inch, B 1380. Read down first column of table to 7, then across 3rd column to .10816.

B or .380.10816=.27184 or C C or .27184+maj0r dia. 1.250"=1.52184 mike size It is believed that the use of the anvil will be apparent to those skilled in the art and it is to be understood that changes in the details of construction and arrangement and combination of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claim.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

A device of the character described for use with 3 a micrometer to measure the pitch line of the threads of various taps, comprising a triangular shaped body portion having three faces and two sides and one edge of the body portion at the faces thereof being nearly sharp, the second edge increasing in width over said first edge and the third edge increasing in width over the second edge and the edges are ground to prevent contact thereof with the root of the threads of the tap to be measured and the faces of said body portion are ground to a 60 angle with relation to the edges, a bushing mounted in said body portion extending through the body portion at right angles to the sides thereof, a shaft positioned in the bushing for rotatably mounting said body thereon and a flat handle having forked ends for mounting the ends of the shaft and the forked ends of the handle being parallel to the sides of the body portion.

CARL RUSSELL. HANS R.KIEL.

4 REFERENCES orrEn The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name Date 1,174,052 Burdick Mar. '7, 1916 1,336,189 Bechler Apr. 6, 1920 FOREIGN PATENTS Number Country Date 510,443 Great Britain Aug. 1, 1939 OTHER REFERENCES Popular Mechanics, page 138, Sept. 1945. 

